(a) Field of the Invention
The present invention relates generally to an improved magazine assembly for a fastener driving tool, and more particularly to an improved magazine assembly with few structural elements and which facilitates assembly and loading and unloading of fasteners.
(b) Description of the Prior Art
As is known in the art, the type of fasteners used in a fastener driving tool varies according to the nature of a workpiece. For instance, T-shaped fasteners and U-shaped fasteners are used in conjunction with different specialized magazines. In the present invention, the magazine assembly is adapted for T-shaped fasteners.
The most widely used magazine assembly for T-shaped fasteners is shown in FIG. 1. The conventional magazine assembly shown mainly comprises a magazine 10, a stop means 11, a pusher means 12, an arrester means 13, a coil spring 14 and a nose portion 15. The magazine 10 includes a guide plate 101 and an abutment plate 102. The stop means 11 is restrained by the arrester means 13 to cover the outer periphery of the magazine 10. The coil spring 14 is insertably provided in the stop means 11. By utilizing the resilience of the coil spring 14, the pusher means 12 is pushed forward to enable fasteners contained in a drive track element 103 provided on the abutment plate 102 to move intermittently toward the nose portion 15 to be driven into a workpiece. Although this structural design has the advantages of using less time and energy, there are some latent problems waiting to be solved.
In the first place, because the conventional magazine assembly consists of quite a number of structural elements, assembly is not easy. In particular, the coupling of the stop means 11 and the pusher means 12 must rely on a fixing pin 16, a torsion spring 17 and a C-ring 18. In addition, the stop means 11 has to depend on the attester means 13 to ensure that its movement's orientation is accurate and that it may not easily drop. The manufacturing cost of this kind of fastener driving tool is therefore high.
In the second place, when a user pulls the pusher means 12 so that the stop means 11 is caused to displace downward to the end of the abutment plate 102 for loading fasteners (not shown), because the pusher means 12 is not provided with any gripping means, the user must use one hand to hold the pusher means 12 and use the other hand to load fasteners. The fastener driving tool is quite heavy, and the resilience of the coil spring is substantially strong, it will be greatly inconvenient to the user who has to support such a great load with a single hand.